In private email, loop-AES user reported that he repeatedly experienced
problems booting encrypted root initrd.gz created with build-initrd.sh. It
turned out that his kernel was configured with cramfs built-in and that this
caused boot to fail. build-initrd.sh creates compressed minix file system on
the initrd. To cramfs, compressed minix file system appears to look like a
cramfs file system. When kernel attempts to detect initrd file system type,
cramfs detects it as cramfs type and attempts to mount compressed minix file
system as cramfs file system. Obviously, that can only fail.
Workaround for this incompatibility is to prevent cramfs code from ever
seeing compressed minix initrd. This can be accomplished in many ways,
including:
a) Configure kernel with CONFIG_CRAMFS=n, or
b) Configure kernel with CONFIG_CRAMFS=m, or
c) Append "rootfstype=minix" kernel parameter. This works only
when using USEPIVOT=1 in build-initrd.sh configuration.
Current version of loop-AES encrypted root instructions do not warn about
this incompatibility, so I decided to post this message here. Next version
of loop-AES will have this incompatibility properly documented.
Regards,
Jari Ruusu <jari.ruusu@xxxxxxxxxx>
-
Linux-crypto: cryptography in and on the Linux system
Archive: http://mail.nl.linux.org/linux-crypto/
